Winter-Swimming and Brown Adipose Tissue Activity in Middel-aged Obese Subjects (WinterBAT). (WinterBAT)

November 7, 2018 updated by: Susanna Søberg, Rigshospitalet, Denmark

The Impact of Winter Swimming on Brown Adipose Tissue Recruitment and Metabolic Health in Middel-aged Obese Pre-diabetic Subjects.

This study investigates repetitive cold-water exposure on brown fat activity assessed by infrared thermography imagine. Furthermore we will assess glucose control upon winter-swimming. Obese prediabetic men and women will be randomized to winter-swimming or control conditions for 4 months.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Brown fat (BAT) is an energy-consuming tissue. Long-term activation of BAT in adults increases clearance of blood glucose and non-esterified fatty acids (NEFA), insulin sensitivity and metabolic rate. Moreover, adipokines released from BAT, known as batokines, represent a promising but currently unexplored area in terms of metabolic regulation. Cooling activates BAT; however, current cooling protocols fail to activate BAT in a large part of the population. Whether this failure in activation is related to biology, inefficient detection or cooling protocols is unknown. With our initial acute cooling study (protocol number: H-16038581), these protocols have successfully been optimized whereupon novel batokines will be identified. Having established a methodology for assessing BAT activity and batokine profiles, a longer-term cooling intervention (winter swimming) will be performed to examine the effect of repetitive cold-water exposure on BAT activity. Obese pre-diabetic subjects will be included in a 4-month supervised winter swimming (WS) intervention.

It is hypothesized, that repetitive cold-water exposure constituted by WS, alters increase BAT activation and volume, followed by improved glycemic control in obese pre-diabetic subjects.

Method The study is a randomized controlled, parallel-group intervention study. The investigator will recruit 30 obese pre-diabetic non-winter-swimmers to participate in a WS intervention group (n=15) or control group (n=15) with no WS activities. Subjects will either be randomized to the WS group, who will winter-swim 4 months, 2-3 times/week including sauna-visits if desired, or control conditions with no WS during the 4 months (October to May).

Main aims

  • To assess whether WS will have an immediate effect on BAT recruitment or function.
  • To assess whether WS will have an effect on glycemic control.

Study Type

Interventional

Enrollment (Anticipated)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Denmark
      • Copenhagen, Denmark, 2100
        • Recruiting
        • Center for Inflammation and Metabolism/ Center for Physical Activity Research
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Waist circumference above 80 cm for women and 94 cm for men.
  • BMI > 25 but <40 kg/m2
  • Age > 40 years.
  • Low to moderate physical activity level (no physical activity or on average 30 minutes of moderate physical activity per day and not more than 3 hours of training pr. Week)

Subjects will be included in either one of these cases after the screening:

  • Fasting plasma glucose above 5.6 millimol per liter (mmoL/L).
  • HbA1C >39 millimol per mol (mmol/mol).
  • 2 hour plasma glucose after a 75 g. oral glucose tolerance test (OGTT) above 7.8 mmol/L.

Exclusion Criteria:

  • Winter swimmer
  • Any history of Cancer,
  • Clinically significant liver, kidney, heart, inflammatory or lung-disease.
  • Pregnancy
  • Taking medication (not for hay fever), including glucose-lowering treatment.
  • HbA1c >55 mmol/mol and/or 2-h plasma glucose in the 75-g OGTT > 15 mmol/L, fasting plasma glucose above 6.9.
  • Iron deficiency
  • Increased International Normalised Ratio for coagulation (INR).
  • Femoral hernia, vene prostheses (pants prosthesis), thrombs in v. Femoralis.
  • Abnormal ultrasound echocardiography of the heart found at the health-examination day.
  • Contraindications to cold exposure including severe Raynauds disease.
  • History of alcohol abuse or use of more than 14 units pr. Week.
  • History of drug abuse, including marihuana.
  • Smoking including occasional smoking.
  • Pacemaker or other electronics implanted in the body.
  • Claustrophobia, communication problems, including understanding the experimental protocol.
  • History of contrast allergy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Winter Swimmers
4 Months of supervised winter swimming.
Behavioral: Winter Swimming
Supervised Winter Swimming in Copenhagen
Placebo Comparator: Control group
No winter swimming activities.
Behavioral: Control group
No winter swimming activities.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in brown adipose tissue (BAT) activity after cooling between Winter Swimmers (WS) and No-Winter Swimmers (NWS).
Time Frame: Difference in peak temperature after 2 hours of cooling.
BAT activity is measured by skin temperature in the supraclavicular BAT depot using infrared thermography imaging. Difference between peak temperature change (peak temperature minus baseline temperature) during 3 hours of cooling is calculated.
Difference in peak temperature after 2 hours of cooling.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in glycemic control after winter swimming
Time Frame: Difference in glucose control after a 2 hour oral glucose tolerance test before versus after 4 months of winter swimming.
Glycemic control is measured by a 2 hour oral glucose tolerance test. Difference in the 2 hour sample will be calculated before and after the 4 months winter swimming intervention.
Difference in glucose control after a 2 hour oral glucose tolerance test before versus after 4 months of winter swimming.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Rigshospitalet, Denmark

Investigators

  • Principal Investigator: Susanna Søberg, PhD-student, Center for Inflammation and Metabolism/Center for physical activity research

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Anticipated)

November 7, 2018

Primary Completion (Anticipated)

June 1, 2019

Study Completion (Anticipated)

June 1, 2019

Study Registration Dates

First Submitted

May 17, 2018

First Submitted That Met QC Criteria

May 17, 2018

First Posted (Actual)

May 30, 2018

Study Record Updates

Last Update Posted (Actual)

November 8, 2018

Last Update Submitted That Met QC Criteria

November 7, 2018

Last Verified

November 1, 2018

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • H-18015882 WinterBAT-Study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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